1. Field of the Invention
The present invention relates to a glassless stereoscopic display and, more particularly, to a glassless stereoscopic display that does not cause color separation and black stripes.
2. Description of the Related Art
In general, stereoscopic displays provide a stereoscopic image based on binocular parallax by separating an original image into a left-eye image and a right-eye image and providing the separated left-eye image and right-eye image to a viewer's left and right eyes, respectively. Stereoscopic displays are roughly divided into displays using glasses and glassless displays. Displays using glasses have a disadvantage in that a user must wear special viewing aids such as polarization glasses. To solve this problem, glassless displays have been developed, which separate an original image into a left-eye image and a right-eye image using a three-dimensional (3D) optical plate, such as a parallax barrier or a lenticular lens sheet, disposed in front of a display panel. Accordingly, a viewer can see a 3D image without special viewing aids. However, such conventional 3D displays using a parallax barrier or lenticular lens sheet suffer from color separation and black stripes.
FIG. 1 is a schematic view illustrating why color separation occurs in a conventional glassless stereoscopic display. Referring to FIG. 1, the conventional glassless stereoscopic display includes a display panel 10 displaying an image, and a 3D optical plate 15 separating the image displayed by the display panel 10 into a left-eye image and a right-eye image. The display panel 10 includes a plurality of pixels 11, each composed of red (R), green (G), and blue (B) colored sub pixels. The pixels 11 display left-eye images L1 and L2 and right-eye images R1 and R2 in an alternating pattern. The left-eye images L1 and L2 and the right-eye images R1 and R2 displayed by the pixels 11 are enlarged by the 3D optical plate 15, such as a lenticlar lens sheet, to be respectively focused on a viewer's left eye and right eye within a viewing distance. Since the RGB sub pixels arranged in an X-direction are also enlarged and focused at the viewing distance, when the viewer moves his head in the X-direction, colors in the image are separated into red (R), green (G), and blue (B) components. Accordingly, the red (R) looks stronger when the viewer is in a position “A”, the green (G) looks stronger when the viewer is in a position “B”, and the blue (B) looks stronger when the viewer is in a position “C”. Such a phenomenon is referred to as color separation, and hinders the viewer from seeing a natural 3D image. Although the 3D optical plate 15 shown in FIG. 1 is a lenticular lens sheet, a parallax barrier can produce the same effect.
FIGS. 2A and 2B are schematic views illustrating why black stripes occur in the conventional glassless stereoscopic display of FIG. 1. Referring to FIG. 2A, a black matrix is typically formed between the RGB sub pixels of the display panel 10. When the left-eye images L1 and L2 and the right-eye images R1 and R2 displayed by the display panel 10 are enlarged by the 3D optical plate 15 to be focused on the viewer's left eye and right eye within the viewing distance, the black matrix is also enlarged and focused in the viewing distance. Referring to FIG. 2B, portions where light intensity drastically decreases are periodically produced in the X-direction. Accordingly, when the viewer moves his head in the X-direction, he perceives black stripes 20 as well as color separation. The black stripes 20 also hinder the viewer from watching a natural 3D image.